Usb cable and method of producing same

ABSTRACT

A method and apparatus for producing a USB cable capable of being fed out of and returned to a cable reel is disclosed along with a cable reel that houses the cable and provides connectivity for the cable.

FIELD OF THE INVENTION

The application claims priority of provisional application 61/166,248filed on Apr. 3, 2009. The present invention relates generally to a USBcord, and more specifically to a USB cord coupled to a retractable reel.

BACKGROUND OF THE INVENTION

Universal Serial Bus, or “USB” is a commonly used term that refers to astandard for connecting two electronic devices or for connecting adevice and a host computer. Using USB technology, a plurality ofperipherals can be connected using a single standardized interfacesocket. Plug-and-play capabilities may also be improved by permittinghot swapping—that is, by permitting devices to be connected anddisconnected without rebooting the computer or turning off the device.Other features of USB technology include providing power tolow-consumption devices, eliminating the need for an external powersupply, and allowing many devices to be used without requiringmanufacturer-specific device drivers to be installed.

In certain scenarios, it may be desirable to have a USB cord on aretractable reel, such that the cord can be extended and retracted intoa reel depending on how and when it is being used.

SUMMARY OF THE INVENTION

The present invention relates to one or more of the following features,elements or combinations thereof.

In one embodiment, a retractable USB reel includes a pair of data wiresplaced next to each other and overlaid with an EMI/RFI shield. The datawires may be twisted around each other. Conductors can also be placedand twisted around the data wires or put in parallel relationship withthe data wires. The resulting conglomerate of wires and shields can thenbe covered with a low friction substance and then an EMI/RFI shield.

In another embodiment, a cord reel is provided with an electricallyconductive material. The cord reel is configured to carry a stationaryUSB coil and a movable USB coil, such that the two USB coils are incommunication with each other.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top view of a flat USB connecting cable according to oneembodiment of the invention;

FIG. 2 is a perspective view of a USB cord reel according to oneembodiment of the invention, the USB cord reel showing the innerelements of the cord reel;

FIG. 3 is a perspective view of a USB cord reel; and

FIG. 4 is a perspective view of one embodiment of the invention withouta jacket.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

As can be seen in FIG. 1, a flat USB cable 10 can include a first datawire 12 and a second data wire 14. First and second data wires 12, 14are illustratively positioned adjacent to each other and twisted aroundeach other. Other wires 16, 18, 20, 22, 24, 26, and 28 may also bepositioned alongside first and second data wires 12, 14. In theillustrated example, other wires 16, 18, 20, 22, 24, 26 and 28 arearranged in a substantially parallel single row on either or both sidesof first and second data wires 12, 14. The various wires 12, 14, 16, 18,20, 22, 24, 26, and 28 are held together with a threaded material.

The present invention comprises a cable management system for organizingand managing a USB cable, and may optionally comprise other cablesand/or wires coupled therewith. Such a management system facilitates theuse and storage of a USB cord in a variety of environments, includingpassenger vehicles.

As can be seen in FIG. 2, the illustrative cable management system 30comprises a cable storage unit 32, a cable reel 34, a cable 36, and aUSB connector 38. A second USB connector or other electronic connector40 may also be provided at the other end of cable management system 30.Additional connectors 39, 41 may also be provided. The cable storageunit 32 may have a tension element disposed within and coupled to reel34, the tension element functioning to resist extraction of the cable 36from the housing.

The cable storage unit 32 may be configured for mounting on a seat, avehicle, or any other type of structure. Similar disclosures of cablestorage units and cable management systems can be found in U.S. Pat. No.5,094,396 to Burke, the subject matter of which is hereby incorporatedby reference, and U.S. Patent Application No. 2007/0262185 to Burke, thesubject matter of which is also hereby incorporated by reference.

In the embodiment shown in FIGS. 2-3, cable storage unit 32 includes aspool or reel 34 upon which a portion of the length of the cable 36 iswound. The cable storage unit 32 also includes a base or housing 40. Thehousing 40 may include a plurality of circumferentially spaced tabs 42configured to enable reel 34 to be rotatable relative to housing 40.Additionally, tabs 42 may he configured to retain the wound portion 44of the cable against reel 34. The inside surface of housing 40 may alsobe coated with an electrically conductive coating.

Rousing 40 may also provide mounting holes 46 to facilitate mounting ofthe cable storage unit 32 underneath a passenger seat or in some otherlocation. It should be understood that cable 36 may include multipletypes of wires and/or connectors. For example, in the embodiments shownin FIGS. 2-3, two connectors 38, 39 and 40, 41 appear at each end of thecable management system 30.

The manufacture and construction of cable 36 is illustratively asfollows and can be seen in FIG. 4. A pair of USB data wires is placednext to each other in such a way as to remain substantially immobilerelative to each other. For example, it is contemplated that the USBdata wires are twisted around each other at a rate of approximately fourtwists per inch. The USB data wires can then be overlaid with a braidedshield 48. Shield 48 functions to substantially remove void spacesbetween the data wires and may further assist in protecting the USB datawires from interference from any adjoining wires and appliances. In oneembodiment, the shield is a helically braided, served shield.Collectively, the USB data wires and the shield are referred to hereinas a “first construe.”

Additional conductors/data wires are placed in close spatialrelationship to the first construct to create a second construct havinga cross section defining a substantially circular periphery. Theadditional conductors may be twisted or fluted helically about the firstconstruct at a lay rate of two twists per inch. Alternatively, theadditional conductors may be positioned alongside and parallel to thefirst construct, without twisting around the first construct. Ifdesirable, “core fillers” may also be used to create a cord that issubstantially round in construction. This “second construct” willideally be formed to have a bend radius of 55 mm or greater.

The second construct is then covered with a low friction substance suchas PFE, followed by second shield, such as an EMI/RFI shield. Thisprocess can ideally produce a USB cable with a bend radius of 55 mm orgreater, a length of at least five meters, and a signal rate of at least1.5 Mb.

It is also of interest to provide a USB cord that has sufficientimpedance for the operation of electronic devices and data components. Asuggested nominal impedance for most data applications is 90 Ohms.Accordingly, one of the goals of the disclosed embodiment is tomanufacture a USB cord that allows for approximately the illustrative 90Ohms impedance.

It is observed that impedance is affected by physical and geometricproperties of the wires and the constructs. The spacing betwveen thewires, as well as the wall thickness of the wire insulation issignificant. Bending the wires also affects impedance. Accordingly, itis significant to hold the USB data wires in a substantially uniformmanner regardless of how the USB cord is positioned or bent.

Additional conductors/wires that are positioned along the USB wires canalso affect impedance. Therefore, the position of such additionalconductors and the shield between the conductors and the USB wires areconsiderations when constructing the USB cord. An additional shieldaround the non-USB conductors may also be desirable. Finally, a braidednylon jacket may be formed on top of entire bundle. This nylon jacketmay affect impedance by putting pressure on the underlying data wires.Furthermore, in a “double served shield” embodiment, impedance may alsobe affected.

The following chart shows various impedances and the resulting declinein impedances in selected “P3” embodiments. The term “no jacket” meansno nylon jacket was used. The term “jacket” refers to a nylon-braidedjacket. Single serve and double serve refer to the number of shieldsaround the constructs inside the cord.

From the data shown above, it can be seen that a data wire with higherimpedance must be used in order to result in a 90 Ohm impedance.Additional notes relating to the construction of the USB cord can befound in Exhibit A, attached hereto and incorporated by reference.

While the disclosure is susceptible to various modifications andalternative forms, specific exemplary embodiments thereof have beenshown by way of example in the drawings and have herein been describedin detail. It should be understood, however, that there is not intent tolimit the disclosure to the particular embodiments disclosed, but on thecontrary, the intention is to cover all modifications, equivalents, andalternatives falling within the spirit and scope of the disclosure.

1. A universal serial bus cord reel apparatus comprising: A cable, thecable comprising a) first and second data wires adjacent to each other,and twisted around each other at approximately four twists per inch; b)a first braided shield surrounding the first and second data wires toprevent electromagnetic or radio frequency interference; c) two or moreadditional conductors adjacent to the shield surrounding the first andsecond data wires, the additional wires being twisted about the shieldat approximately two twists per inch; d) a polytetrafluoroethylene coverenclosing the additional conductors and first and second data wires; ande) a second shield enclosing the polytetrafluoroethylene cover; wherebythe cable has an impedance of approximately 90 ohms; a universal serialbus connector at each end of the cable; a housing; a reel attached toand rotatable with respect to the housing for accepting the cable; aspring mounted between the housing and the reel for biasing the rotationof the reel in one direction for retracting the cable; a ratchetattached to the housing for selectively restraining rotation of the reelwhereby the cable may be maintained in an extended position, orretracted and wound on the reel.
 2. A method for manufacturing auniversal serial bus cable comprising the steps of: Placing first andsecond data wires adjacent to each other; Twisting the first and seconddata wires about each other at approximately four twists per inch;Covering the twisted first and second data wires with a braided shield;Placing one or more additional data wires in close proximity to theshield; Forming a circular cross-section of the first and second datawires, the braided shield, and the one or more additional data wires byeither twisting or helically fluting the one or more additional datawires about the braided shield at approximately two twists per inch, sothat the resulting structure has a bend radius of at least approximately55 millimeters; Coating the braided shield and one or more additionaldata wires with a low-friction substance; Covering the low-frictionsubstance with a second shield resisting radio-frequency andelectromagnetic interference, so that the resulting structure has animpedance of approximately 90 ohms and a signal rate of at leastapproximately 1.5 megabytes per second.
 3. A retractable UniversalSerial cable apparatus, the apparatus comprising a housing, a spoolpositioned within the housing and arranged for rotation relative to thehousing, a stationary cable including a universal serial bus connectorextending from the housing, a retractable cable including a universalserial bus connector capable of being extended from and retracted intothe housing and further capable of being in electrical communicationwith the stationary cable, and a ratchet mounted on the housing, theratchet having an engaged position wherein the ratchet is in electricalcommunication with the spool and the ratchet having a disengagedposition, wherein the ratchet is not in electrical communication withthe spool.
 4. The apparatus of claim 3, wherein the ratchet comprises aconductor lead and the spool has a conductor mounted thereon.
 5. Theapparatus of claim 4, wherein in the engaged position, the conductorcontacts the conductor lead.
 6. The apparatus of claim 4, wherein theratchet further comprises a second conductor lead and the spool has asecond conductor mounted thereon.
 7. The apparatus of claim 4, whereinthe conductor is prevented from contacting the conductor lead when theretractable cord is being extended from the housing.
 8. The apparatus ofclaim 3, wherein the stationary cord is in electrical communication withthe ratchet.
 9. The apparatus of claim 3, wherein the ratchet comprisesa tooth in radial alignment with a wall of the spool.
 10. The apparatusof claim 3, wherein the cable comprises at least first and second datawires adjacent to each other, and twisted around each other atapproximately four twists per inch, and a first braided shieldsurrounding the first and second data wires to prevent electromagneticor radio frequency interference.
 11. The apparatus of claim 10, whereinthe cable further comprises two or more additional conductors adjacentto the shield surrounding the first and second data wires, theadditional wires being twisted about the shield at approximately twotwists per inch, and a polytetrafluoroethylene cover enclosing theadditional conductors and first and second data wires.
 12. The apparatusof claim 11, wherein the cable further comprises a second shieldenclosing the polytetrafluoroethylene cover, whereby the cable has animpedance of approximately 90 ohms.
 13. A universal serial bus cablereel apparatus, the apparatus comprising a housing, a spool having aconductor coupled thereto, the spool being positioned within the housingand arranged for rotation relative to the housing, a ratchet positionedto selectively engage the spool, and a retractable cable at leastpartially wound around the spool, the retractable cable being extendablefrom the housing and having a universal serial bus extend from each end,wherein an electrical current is passed through a conductor coupled tothe spool.
 14. The apparatus of claim 13, wherein the ratchet comprisesa conductor
 9. lead configured to make contact with the conductor on thespool.
 15. The apparatus of claim 14, wherein the ratchet furthercomprises a second conductor lead and the spool has a second conductormounted thereon.
 16. The apparatus of claim 13, wherein the conductor isprevented from contacting the ratchet when the retractable cord is beingextended from the housing.
 17. The apparatus of claim 13, furthercomprising a stationary cord in electrical communication with theratchet.
 18. The apparatus of claim 13, wherein the ratchet comprises atooth in radial alignment with the spool.
 19. The apparatus or claim 13,wherein the cable comprises at least first and second data wiresadjacent to each other, and twisted around each other at approximatelyfour twists per inch, and a first braided shield surrounding the firstand second data wires to prevent electromagnetic or radio frequencyinterference.
 20. The apparatus of claim 19, wherein the cable furthercomprises two or more additional conductors adjacent to the shieldsurrounding the first and second data wires, the additional wires beingtwisted about the shield at approximately two twists per inch, and apolytetrafluoroethylene cover enclosing the additional conductors andfirst and second data wires.
 21. The apparatus of claim 20, wherein thecable further comprises a second shield enclosing thepolytetrafluoroethylene cover, whereby the cable has an impedance ofapproximately 90 ohms.